The present invention relates to casts, and more particularly to padding for such casts.
Fairly standard procedures have been used by physicians for many years to form a cast on a patient's extremity. Such procedures have been commonly accepted with little afterthought, since there have been few significant advances in the field for a long time which would present viable alternatives. However, as discussed below, the current practice in such matters is deficient in many respects.
Thus, in the case of an arm cast, a sleeve of tubular knit, two-way stretch material, termed stockinette, is cut to length for placement over the patient's arm and hand, and an opening is cut in a side of the sleeve to receive the patient's thumb. The stockinette material defines the inside of the finished cast to provide a comfortable surface for the patient. Next, an elongated strip of sheet wadding or cast padding, which may be hereinafter termed "wadding", is wound in a helical and circular fashion about the patient's arm and hand over the stockinette material. Typically, the wadding may be wrapped in about three layers, and both the stockinette material and wadding initially extend beyond the desired distal border of the cast. The wrapped sheet wadding provides padding for the patient beneath plaster of the finished cast. However, when the wadding is wrapped about the patient's thumb, two unwrapped triangular regions frequently remain open on the front and back of the hand, termed the "intern's triangle", due to the difficulty of wrapping the wadding in this region of the hand. Further, the stockinette material does not extend along the thumb.
An elongated strip of plaster is then wrapped over the sheet wadding to form the outer part of the cast. At this time, a number of difficulties arise in the procedure. First, the plaster is permitted to contact the patient's skin through the intern's triangles formed by the wadding, resulting in discomfort and possible cutting of the skin as the patient moves his thumb in the cast during healing. Second, as the plaster is wrapped about the patient's thumb, the plaster itself may form open intern's triangles on the front and back of the hand resulting in a region of weakness in the final cast which extends between the apices of the opposed triangles.
Next, it is extremely desirable to immobilize the hand into a position of function by the cast while maintaining the transverse metacarpal arch in the hand. Generally speaking, the desired position of function may be visualized as the configuration assumed by the hand while grasping a ball the size of a small grapefruit. In this position, the hand may be immobilized for extended periods of time without contractures occurring in the fingers and thumb. Further, by maintaining the transverse metacarpal arch, the thumb is placed into a position opposing the little finger to prevent loss of function between the fingers and thumb. However, in order to accomplish this result in the past, it has been necessary for the physician to depress the plaster in the palm as it sets by applying continual pressure with the thumb against the wet plaster into the palmar depression or recess, i.e., the low area of the hand intermediate the group of muscles at the base of the thumb (thenar eminence) and the eminence proximal the base of the little finger (hypothenar eminence). When the cast finally sets, a depression of the cast is formed in the palmar recess to maintain the transverse arch, but at the cost of time and inconvenience to the physician.
Further, as the plaster is wrapped, the plaster layers form a tapered or feathered distal end which must be removed from the cast, since the end would otherwise break apart during use of the cast. Hence, the physician must wait until the cast sets, and then trim the plaster and sheet wadding generally along the location of the distal palmar crease in the hand. Next, the physician must obtain additional wet plaster, place it over the tacky plaster adjacent the distal trimmed edge, turn a distal end section of the stockinette material over onto newly wet plaster, and place further wet plaster over the turned end section of the stockinette material in order to finish the distal end of the cast. It is apparent that such a procedure causes a great deal of inconvenience to the physician accompanied by loss of time. Even when trimmed, the cast may be thinner than desired at the distal end. Further, it is noted that the stockinette material does not extend along the thumb, which precludes finishing of the plaster around the thumb in this manner. Hence, the wadding may hang out of the cast in this area, and due to a natural tendency for some patients to pull out the wadding, the cast may eventually become loose.
Similar procedures are utilized to form a cast on the patient's foot. In particular, it is necessary to trim and finish the distal end of the cast. In certain instances, it is necessary to utilize an insert below the toes to form a toe plate for the cast which results in difficulty during formation of the cast. Further, it is desirable to protect the heel area by padding without an excessive amount of material above the ankle which may result during wrapping of the heel, in addition to fitting the recesses in the foot posterior the opposed malleolii and also protect the malleolii.